Diamond-holding tool



March 10, 1942. I DlNHOFER 2,275,511

' DIAMOND-HOLDING TOOL Filed ma 7, 1941 INVENTOR RNEY Patented Mar. 10, 1942 UNITED STATES PATENT OFFICE DIAMOND-HOLDING TOOL Julius Dinhofer, New York, N. Y. Application May 7, 1941, Serial No. 392,197

3 Claims.

This invention relates to diamond-holding .tools of the character employed for grinding culty in holders in which they must be very securely held during the hard use to which the same are put.

As pointed out in my co-pending application above mentioned, I propose to first shape the diamond in such a way that it may be securely gripped ina holder prepared for its accomodation and in which it may be reversed or shifted when required to present new, clean, pointed ends into operative position.

The present invention contemplates the provision of a holder for such a prepared diamond, and particularly a diamond of octahedron or bipyramidal shape, and the primary object of the present invention is the provision of a holder which will securely and firmly engage such a diamond and hold it effectively against either rotative movement in the holder, or dislodgment during extensive and hard use. The invention also contemplates the provision of such a holder in which the diamond is removably held, whereby it may at any time be released from the holder and shifted in the same to locate a fresh pointed end in operative position.

These and numerous other advantages are attained by the structure, a more particular description of which willappear hereinafter an i be setforth in the appended claims.

In the accompanying drawing, forming a part hereof, Fig. l is a sectional view ofa holder and Fig. 5 is a side elevation of the holder; and Fig. 6

is a side elevation of the holder with the clamp and diamond removed.

In the drawing, l indicates the body of the holder which may be of any suitable shape and i is illustratively shown in the form of a cylindrical rod having a reduced portion 2 provided at its end with a substantially square opening 3, surrounded by the four inclined surfaces 4, which 55 co-operate in the formation of an angular seat, upon which the lower pyramidal portion 5 of the diamond 6 Tests. The end portion of the holder surrounding the seat 4, is provided with the four radial slots .7 which lend resiliency to this portion of the holder. The diamond 6 is preferably of octahedron shape as shown in Fig. 2 and is thus bipyramidal and has six pointed ends 9, any of which may be projected uppermost to occupy the position of that shown at 8 and be thus operative against a grinding wheel or other element for dressing the same. It will be obvious that the diamond may be positioned in any one of several ways in the holder to cause any of the pointed ends or terminals 9 to occupy the position of that shown at 8 in Fig. l.

The diamond is clamped upon the seat 4 by means of a clamping member or cap [9 which fits over and encloses the end of the holder 2, said cap member having an endwall ll in which is provided a substantially square opening I2, the edges of the same being inclined as indicated at l3 to fit over and engage against the inclined walls of thesecond pyramidal portion of the diamondin the manner clearly shown in Fig. l.

The clamp or cap member Iil is provided with inclined inner surfaces M which engage against co-operating surfaces I5 on the member 2 so that when the cap member is adjusted as will be here- 0 inafter explained, the split portions of the holder surrounding the seat 4 will be urged toward one another to cause them to firmly engage against the lower pyramidal portion 5 of the diamond whilethe diamond is firmly held against the seat 4 by means of portions of the end wall I l surrounding the opening I2', said end wall being provided with four radial slits IS which divide the end wall into four resilient tongues I! that engage against the inclined portions of the upper pyramidal part of the diamond. Through the arrangement described, it will be apparent that the diamond is very firmly held at its four sides by means of the tongues H at the top pyramidal portion of the same, and at its lower end by the four inclined surfaces 4 of the seat against which the lower pyramidal part of the diamond is held by the pressure of the tongues I 1 on the clamp The clamp is held against rotative movement by means of the projecting pins l9 engaged by slots IS in the walls of the clamp l0. At its end remote from the Wall II, the clamp Ill is formed with a radial fiange 20 for engagement under the inwardly extending flange 2| on an adjusting ring or nut 22, internally threaded for reception on the threaded portion 23 of the holder I. The adjusting ring or nut 22 is exteriorly knurled and also provided with a recess 24 for engagement by a suitable tool to enable the ring to be adjusted and the clamp It to be tightened or loosened as desired.

In assembling the tool, the diamond of the octahedron or pyramidal shape shown, or of other suitable conformation, is first fitted upon the seat in the holder with the four angular sides of one of the pyramids resting against the inclined surfaces 4 of the seat. The cap or clamp is next fitted over the diamond and one of the pointed ends 9 of the diamond will project through the opening I2 in the clamp and occupy the operative position indicated at8 in Fig. 1. When fitting the clamp in position, the same is placed so that the slots IE will engage over the pins I9. When in this position, the four tongues ll of the clamp will engage against the four inclined surfaces of the upper pyramidal portion of the diamond as shown in Figs. 1 and 3. It is next necessary to rotate'the nut 22 to cause it to draw the clamp it firmly down against the diamond, the clamp at the same time forcing the split portions of the holder inwardly to cause them to co-operate with the clamp 10 in very effectively holding the diamond against either rotative movement or misalignment in the holder.

When the tool has been used for some time and the projecting point becomes worn, it is merely necessary to loosen the nut 22, remove the clamp l0 and shift the diamond to another position with another one of the six pointed ends protruding at 8, and then tighten the clamp.

With an arrangement of this kind, the holder will last indefinitely; will grip the diamond firmly and securely; will permit the diamond to be adjusted and shifted to any of the six positions necessary to project the several points of the diamond outwardly whenever required, without the use of special tools or skill. The co-opcrating inclined surfaces of the holder and clamp serve to automatically properly position the diamond in the holder so that no special care or effort need be expended in accurately positioning the diamond. These and many other advantages follow through the use of the improved construction, and it is obvious that many changes in structure and design may be made without dethe facet-contacting surfaces in which the meeting portions of the several facets extend, a cap fitted over the seat, said cap having an end wall provided with a square opening to permit protrusion of one pointed end of the diamond,'said cap having four angular surfaces for engagement against the outer facets of the diamond, said cap having angular slits between said surfaces in which the meeting portions of the several outer facets are located, the slits in the cap being located above those in the seat. I

2. A tool of the character described comprising, a bipyramidal diamond, a holder including a threaded base portion having a recessed seat provided with angular surfaces against which under facets of the diamond may rest, said seat having radially extending slits located between the facet-contacting surfaces in which the meeting portions of the several facets extend, a cap fitted over the seat, said cap having an end wall provided with a square opening to permit protrusion of one pointed end of the diamond, said cap having four angular surfaces for engagement against the outer facets of the diamond, said cap having angular slits between said surfaces in which the meeting portions of the several outer facets are located, said slits being located above those in the seat, a clamping ring adjustable on the threaded base portion, means on said clamping ring for engaging the cap to move it toward the seat, and co-operating means on the cap and base portion for preventing rotative movement of the cap when being moved toward the seat by adjustment of said clamping ring.

3. A tool of the character described comprising, a bipyramidal diamond, a holder including a threaded base portion having a recessed seat provided with angular surfaces against which the under facets of the diamond rest, said seat having radially extending slits located between the facet-contacting surfaces in which the meeting portions of the several facets extend, a cap fitted over the seat, said cap having an end wall provided with a square opening to permit protrusion of one pointed end of the diamond, said cap having four angular surfaces for engagement against the outer facets of the diamond, said cap having angular slits between said surfaces in which the meeting portions of the several outer facets are located, an adjusting member rotative on the threaded portion of the holder for adjusting the cap relative to the holder, the cap being slotted inwardly from one of its ends, and radially extending pins on the holder entrant into said slots to hold the cap against rotative movement while the same is being adjusted relative to the holder. JULIUS DINHOFER. 

